1. Technical Field
The present invention relates to climate control humidifiers and more specifically to a high pressure water injection humidifier having a constant speed motor and a precision orifice.
2. Background Art
It is well known that low ambient humidity in a building space leads to occupant discomfort, possible health problems, and electricity discharges. Such low ambient humidity also causes damage to furniture, papers, artwork, and musical instruments contained within the building. To obviate these problems, it is common practice to employ devices for adding moisture to the air. In this regard, a wide variety of humidification devices are commonly employed.
For example, evaporative type systems have been installed in the furnace plenum or heating ducts so that heated air is forced to flow through and about sponge-like members that are maintained in a moist condition by placing them in contact with a water reservoir. Such reservoirs must be maintained at a preset level to ensure sufficient moisture content in the sponge-like members. It is also known to utilize a steam generator in combination with a forced air heating system to place water vapor into the heated air stream. The steam is generated by use of a submerged heating element in a water reservoir tank. In each of these systems, the reservoir water level must be maintained at a predetermined level.
One of the specific problems associated with these water reservoir systems is that they provide a tank of standing water that can be a breeding ground for bacteria, molds, and other unhealthy agents.
In response to this problem, steam injection humidifiers have been developed. These systems connect to a continuous pressurized source of water such as a municipal water hookup, convert that water into steam, and spray that steam through a nozzle directly into the heated air system. However, these steam injection systems present other problems such as the corrosive nature of steam, especially when operating from a non-filtered water supply, the amount of energy required to convert water to steam quickly enough to provide a continuous supply of steam, and the danger of steam leaks.
In the associated field of residential air cooling systems (e.g. air conditioning); an adiabatic evaporative cooling process is used in which water is sprayed into the air without adding or extracting heat. Those knowledgeable in the field will recognize that when an unsaturated airflow is passed through a water spray, water will be evaporated and pass into the airflow as water vapor as long as the saturation point, for a given ambient temperature, is not reached. The heat required for such evaporation, latent heat of evaporation, comes only from the air. Accordingly, ambient air temperature is reduced and moisture content is increased without increasing the heat content of the air; also known as a constant enthalpy process.
Water injection humidification has been attempted, such as for example by a “Humid-A-Mist™” system manufactured by Galmar Enterprises Inc., of New Lenox, Ill. However such a system injects water at a typical residential water supply pressure of between 50 and 100 pound per square inch (psi) which disadvantageously results in relatively large water droplet sizes.
There is a non-associated field of water-jet cutting in which is known a method of cutting materials using a jet of water. Such cutting can be done for soft or low density materials, such as foam, using water only, or for hard dense materials, such as tool steel, by adding an abrasive to the water-jet. The water is forced through a precision orifice to create a well defined stream of water, typically produced under pressures of 40,000 to 60,000 PSI (pounds per square inch). The pump high-rate water flows and extreme high water pressures associated with water-jet cutting are not desirable for residential humidification.
To solve the aforementioned problems associated with the existing state of the art in residential humidification systems, the present invention injects atomized water directly into an operational airflow, such as a heated airflow from a forced air heating system or alternatively an unheated airflow from a stand-alone fan. I have discovered that using a relatively high water pressure, such as 1000 psi, in conjunction with a low-rate water flow, such as 1 gallon per hour, and a precision orifice gives unexpected and desirable results that are directly applicable to residential humidification. Advantageously, preferred embodiments of the present invention incorporate several features to protect against water leakage, indicate system faults, provide water flow indication, and establish humidification profiles based on outside air temperature.